Superheater arrangement for cylindrical shell boilers



`April 18, 1933 w. H, ARMAcosT SUPERHEATER ARRANGEMENT FOR CYLINDRICALSHELL BOILERS Filed April 25, 1932 2 Sheets-Sheet 1 :NVE T R WillowXfmwst BY Q KM ATTORN EY Apri11s,193s., w H ARMACOST 1,903,970

SUPERHEATER ARRANGEMENT FOR GYLINDRICAL SHELL BOILERS Filed April 25,1932 2 Sheets-Sheet 2 o@ fn oo 0000330000 lNVENTOR Wi l bur H. Ananas?ATTORNEY Patented Apr. 18, 1933 UNITED WILBUR H.ARMAGOST, 0F NEW Yon-x;N. Y., AssIGNoR To THE SPERHEATER 00M; e

PANY, oF NEW YQRK, N. Y. ,n 1

Appliaton mea April 25, 1932.', semina. 607,334.

A number of superheater arrangements have' been proposedfor boilers ofthe Cylindrical drum type having one or more return fire-tubes and thelire-box beneath and outside the drum. The prior superheaterarrangements for such boilers have either developed excessive metaltemperatures when the boiler` is being forced Vor have required a"relatively large amount of tube surface to produce the desired degree ofsuperheat. Many of such arrangements,- moreover, have been diiii'cult toapply to a boiler which may have' been installed without a superhea-ter.`A

It is the principal object of my invention to provide alsuperheaterarrangement' for eit'ernally fired drumtype fire-tube boilerswhich shallavoid theabove mentioned diff fioul-ties.

The novel featuresy of my invention are pointed out in the appendedclaims. odenhowever, that the invention, together withfits objects andadvantages, may bel more clearly understood, II will new describe indetail and in connection'withy the accompanyingAr drawings severalarrangements of boiler andi superheater selected by1 way of example'from among a number of possible embodimentsof my invention. Inlthedrawings,-

Fig. l is an elevational view of a horizontal return tube boiler'having! a superheater inaccordanc'efwith my inventionr applied thereto.Y

Figf2- isA av section on theVl line 2-'2 of Fig.

1, looking inthe direction of the arrows.,

Ffig. 2Agis' a detailfplan View of oneof the turnbuckles appearing inFig. 1'. A i

l-igwlis a fragmentary view offal boiler similar tothat of Fig. 1andihaving'a modiied form of superheater associated therewith. 1 v

Fig'. t is afvertic'alv sectional view on the linef off Fig. 5,'y ofanotherY form of Aboile'rbut'having a' s'uperheater in accordance withmy invention' associated there-V vWith.

Fig.' 5 is an elevationaltview of the" apparatus: shown'in Fig. 4. l v

Referrin'glmore particularlyto Figs. l" and 2, -10 is a boiler Yhaving ahorizontal shell 11 of cylindrical form and having-a furnace chamber 12and a lire door 14 at the front end'of the boiler setting; Heating gasesfrom furnace 12 pass rearwardly from the -f'u'rnace beneaththe shell 1'1to the rear e-nd thereof and' thence vpass thrux one or more firetubeswithin the shell 11 to a' breeohing le at its'front end and thenceout thru stack 161 As appears in Fig. 2,y boiler 10 has' a large numberof comparatively small fire tubes 18, 18, but I do not limit myself tothis.`

ln'aocordan'ce' with oneform of my inven'- tion, the superheater 20`is'placedonthe outside of the boiler shell' somewhat to the rear v ofthefurnace 12. Superheater 20 comprises a number of units 22,'22, ea'ch'ofwhichfis'bent tothe same' con-tour as' the external surface A ofthe'she'll 11'. In'the'arrangement"shown7 steam passes'from boiler 10thru a' pipe'24 to lends itself however toa'm'ethod'of supportsv ing thesuperheater whereby its positioncan f be very conveniently'adjusted. Inthe ar'- rangenient shownfcurvedrods v32, 32 are coni neeted toheaders26 and28 at pointsf, 34

v and run upwardly paralllfto the surface'of Y the shell'll topointsatthetopof such'shell wherey the rods 32fp`ass' thru t'urnbuckles36, 361. one of turnbuekles 36 isiillustrafed in detail infFig'. 3."Rodsl 32-are`threaded'at' their ends andv eziteiidfthru: and beyond theturnbu'c'lles so that nuts 38,'f38'on therods "32 can be adjusted't'on'ot only cause'rods32 to supporti the 'superheater 20 on shell l1but also Vto determine the'v distance of* the elements 22 from the'outer surfaee ofl the boiler' shell.

By changing the distance" between the ele:- m'ents'22 and the'drum,thetenperature of 'the steamdelivere'd from the superheater' at agivenloadlonthe boiler will` be varied'du'eto the fact thatV the counterradiation from l`the elements 22 to the water cooled shell 11 varieswith such distance.

Preferably the headers 26 and 28 lie slightly above the horizontalcentral plane of the boiler so that they may be installed in an existingboiler plant with a minimum disturbance of the setting. The ordinaryhorizontal return tubular boiler has a setting which in-V cludes sidewalls 40, 40 and the boiler shell has brackets 42,42 fixed thereto whichtrans-Y fer the weight of the boiler to side walls 40 at a levelapproximately that of the horizontal central plane of the shell.Therefore, a superheater in accordance with my invention can be adaptedto an existing installation merely by tearing out two smallV holes inthe setting on each side.' After the headers and units have been putinplace, such holes can be easily patched up with a minimum amount oflabor.

Another advantage of bendingthe units 22 to the same contour as thatofthe boiler drum is that it makes it possible, when there is verylittle clearance, to install such units by first placing them in aninverted position over the top of the boiler and then sliding themaround the drum. V

The arrangement shown in Fig. 3 is the same as that in Figs. 1 and 2except lthat the superheater units 22a are not all of the same length,some having a greater radius of curvature than others. As shown, theunit nearest the fire-box has the shortest radius and lies nearest theboiler shell 11, and those progressively farther from the fire-box areprogressively longer and lie farther away from the shell 11, so thatelements22a, as shown, shield each only slightly from the gas flow. Thearrangement of 3 therefore is well adapted to produce a'highdegree ofsuperheat. Moreover, the` unit 22a which is farthest from the furnacebeing also farthest fromvthe shell 11, the metal and thevseveral Vunits22a are at nearly the same temperature.

In the arrangement of Figs.4 and 5, the boiler 10a has a cylindricalshell portion 11a beneath which is a furnace chamber 12a. .At the rearof furnace 12a boiler 10a has a shell portion 11b having an ovalcross-section, and within which is a group of fire tubes 18a forconducting hot gases from furnace 12a to a smoke chamber 42 at the rearof boiler 10a. From chamber12a, the gases flow thru tubes `1,8 to abreeohing 14 at the front ofthe boiler.

In the arrangement illustrated in Figs. 4 and 5, thesuperheater liesbeneath the-boiler section 11a!l and above the lire-chamber 12a. Thesuperheater elements 22 are preferably of exactly the same type as thoseillustrated in Fig.V 1, but owing to their location, the superheater ofFigs. 4 and 5 has a partly radiant characteristic. If desired, thesuperheater elements 22 of Figs. 4 and 5 may be p-laced adjacent thefront wall of furnace chamber 12a to thereby produce a superheaterhaving almost an entirely radiant characteristic.

It will be seen that the superheaters 20 have their units 22 connectedto headers 26 and 28 in two parallel rows so that alternate units havetheir ends bent out away from the drum and into the same transverseplane as one of the other units. connect into headers 26 and 28respectively at the ends of the latter. Furthermore, the drawings showthe units 22 as connected to the headers 26 and 28 by disconnectablejoints. It will be understood', however, that I do not limit myself toany of these features.

It will be evident also that the adjustment of superheater units towardor away from the generating surface of the boiler as to which they liein radiating relationshipnecessarily affects the iinal steamtemperature.

I find that4 a material change. may bemade 646,071, filed December 71932, for superheater with adjustable counterradiation.

It is evident further that the balljoints shown between thesuperheater'units and headers are adapted to permit the -units to beswung somewhat in their seats andthat lsuch swinging oryadjustment maybe used to move the units clos/er together or farther apart to therebyVvary the effective heating surface of the superheater. However, the

units illustrated herein happen to be of such 'form that the resultingchange is small and I have not claimed such feature in this application,but have so done in my co-pending application Ser. N o. 653,254, filedJanuary 24, 1983, for superheater boiler in which the units have adifferent contour.v

What I claim isz,

1. The combination with a boiler having a horizontal cylindrical shellportion, of means for passing heating gases along th elower outersurface of said portion,and a superheater having tubes running beneathsaid portion from side to side thereof and'each substantially parallelto its outer surface.

2. The combination as set forth in claim 1 and in which the tubes of thesuperheater are arranged in a single layer.

3. The combination as set forth in claim 1 together with headers for thesuperheater tubes arranged on a plane abovethe horizon'- tal plane thruthe centre of the boiler.

4. The combination with a boiler having a horizontal cylindrical shellportion, of means for passing heating gases along the lower outersurface of said-portion,and a Also, pipes 24 and 30I superheater havingtubes running beneath said portion from side to side thereof and eachsubstantially parallel to its o`uter surface but having said tubesprogressively farther Jfrom said-shell in the direction of flow of theheating gases.

In testimony Whereofl aHX my signature.

VILBUR H. ARMACOST.

